Bidirectional U-shaped coal-mining method of thick coal bed by gateway layout along stability layer

Abstract

The invention relates to a bidirectional U-shaped coal-mining method of a thick coal bed by gateway layout along a stability layer. The method comprises the following steps of: firstly, tunneling all gateways of a mine along the stability layer so that top plates of the tunnels form the stability layer of the coal bed; and arranging actual mining gateways along the stability layer so that workingsurfaces form a bidirectional U shape along the lengths and the advancing directions, wherein a three-section actual mining process, including sapping, leveling and climbing, is adopted on the actualmining of the working surfaces along the lengths and the advancing directions. The method radically solves the difficulties in tunneling and supporting of gateway layout along soleplate in a thick coal bed in the prior art, lessens the coal pillar loss among adjacent working surfaces and is beneficial to the gas drainage of the working surfaces particularly at an upper corner. The invention is suitable for the fully-mechanized mining with large mining height and the sub-level caving mining of the loose and broken thick coal bed.

Description

technical field [0001] The invention relates to a thick coal seam coal mining method, in particular to a two-way concave-shaped coal mining method in which soft and broken thick coal seams are distributed along stable layers. Background technique [0002] Existing thick coal seam mining methods are divided into three types: layered mining, top-coal caving mining and fully-mechanized mining with large mining height. Layered mining was widely used before the 1980s. However, due to the large amount of roadway excavation, low work efficiency, high production costs and the difficulty of roadway excavation, goaf accumulation of water, natural combustion of gas and coal, etc. impact, has been less applied. Fully mechanized mining with high mining height and top-coal caving mining are the main methods of thick coal seam mining. In the current fully mechanized mining with high mining height and top-coal caving mining, the roadways such as the upper and lower troughs and cut holes o...

AI Technical Summary

Problems solved by technology

In the current fully mechanized mining with high mining height and top-coal caving mining, the roadways such as the upper and lower troughs and cut holes of the mining face are arranged along the coal seam floor. The obvious defect of this arrangement is that when the bottom coal seam is soft and broken, the roadway Excavation and support are very difficult; as the thickness of the coal seam increases, the width of the required section coal pillar increases

In addition, when the upper and lower grooves are arranged along the coal seam floor, it is not conducive to the discharge of gas from the working face, especially the upper corner.

[0003] In view of the above problems, the existing technology adopts advanced grouting, advanced pipe shed and advanced bolt to control the head-on roof leakage during excavation, but this seriously affects the excavation speed of the roadway, and the control effect on the stability of the surrounding rock of the roadway is not good.

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